<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            padding: 0;
            margin: 0;
        }
        
        body,
        html {
            height: 100%;
        }
        
        div {
            /* width: 500px; */
            /* height: 600px; */
            background-color: peru;
            height: 100%;
        }
    </style>
</head>

<body>
    <div>
        哈哈哈哈
    </div>
</body>

</html>